1. Field of the Invention
The present invention relates to a processing liquid applying apparatus which applies a processing liquid to a surface of a processing liquid transfer roller and transfers the processing liquid to a transfer medium (for example, printing paper and recording sheet), and an image-forming apparatus provided with the processing liquid applying apparatus.
2. Description of the Related Art
For example, in an image-forming apparatus (for example, printer and facsimile) based on the “ink-jet system”, the inks, which are discharged from the nozzles, are adhered or deposited onto the surface of the printing paper. In this situation, the inks are not preferably deposited onto the printing paper depending on the type of the inks or the printing paper, and the image is blurred and/or the color development is deteriorated in some cases. Accordingly, in the case of a conventional technique, as disclosed in Japanese Patent Application Laid-open No. 2006-346534 (FIG. 12), the blurring of the image is avoided, and the deterioration of the color development performance is avoided by previously applying a processing liquid to the surface of the printing paper.
A liquid applying apparatus disclosed in Japanese Patent Application Laid-open No. 2006-346534 includes an applying roller which applies a processing liquid to a sheet member while rotating in a predetermined direction, and a liquid applying section which applies the processing liquid to the surface of the applying roller. The liquid applying section includes a space-forming member which forms a hermetically closed space with respect to the applying roller, an annular abutting member which seals the circumferential edge portion of the hermetically closed space, and a pressing member (spring) which supports the space-forming member and the abutting member and which presses them toward the applying roller. The processing liquid is supplied into the hermetically closed space, the applying roller is rotated, and thus the processing liquid is applied to the surface of the applying roller which constitutes a part of the hermetically closed space.
According to the conventional technique described above, a mechanism, which applies the processing liquid to the surface of the applying roller, can be easily constructed. However, the space-forming member and the abutting member are merely supported by the pressing member (spring). Therefore, the spacing distance between the abutting member and the applying roller cannot be maintained to be constant and/or the spacing distance cannot be appropriately changed. It is impossible to optionally and preferably adjust the applying amount of the processing liquid with respect to the applying roller.
For example, when the applying amount of the processing liquid is excessively increased in the “transfer mode” in which the processing liquid is transferred from the applying roller to the sheet member, it is feared that a long period of time may be required to dry the processing liquid transferred to the sheet member and/or the processing liquid, which remains on the surface of the applying roller, may inhibit the next transfer process. Therefore, it is necessary that the applying amount of the processing liquid should be stabilized to an appropriate amount. In the case of the conventional technique described above, the abutting member is moved in the tangential direction of the applying roller in accordance with the rotation of the applying roller, and the spacing distance, which is provided between the applying roller and the portion of the abutting member positioned on the downstream side in the direction of rotation of the applying roller, is undesirably widened. Therefore, a tendency arises such that the applying amount of the processing liquid is not only stabilized, but the applying amount is also increased undesirably. On the other hand, in the “cleaning mode” in which the applying roller is cleaned, it is desirable that the applying amount of the processing liquid applied to the applying roller is “relatively large” in order to wash out the foreign matter (paper dust or the like) adhered to the applying roller. In the case of the conventional technique described above, it is impossible to appropriately change the spacing distance between the abutting member and the applying roller. Therefore, it is impossible to intentionally increase the applying amount of the processing liquid in the “cleaning mode”, and it is impossible to obtain any sufficient cleaning effect.